1. Field of the Invention
A twin clutch device includes a first clutch of a multiple disc type which includes a first clutch outer formed in a bottomed cylindrical shape while having an annular plate portion on one end thereof that is rotated due to power transmitted from a power source. A second clutch of a multiple disc type includes a second clutch outer which is rotated together with the first clutch outer and is coaxially arranged inside the first clutch in the radial direction. One of the clutch inners, which are respectively provided to the first and second clutches, is arranged between a clutch constituting member which constitutes a portion of the outer of the first and second clutches and the annular plate portion in a state wherein the clutch constituting member is relatively rotatable with respect to the clutch inner. The present invention relates to a twin clutch device which includes a first clutch for obtaining a connection state by a spring force of a first clutch spring, and a second clutch which is arranged coaxially with the first clutch and obtains a connection state by a spring force of a second clutch spring. The present invention also relates to a twin clutch device which includes a first clutch of a multiple disc type which has a cylindrical portion and a first clutch outer which is rotated due to the power transmitted from a power source. A second clutch of a multiple disc type is provided which includes a second clutch outer which is rotated together with the first clutch outer and is arranged coaxially with the first clutch.
2. Description of Background Art
A twin clutch device in which a second clutch is coaxially arranged radially inside a first clutch which includes a bottomed cylindrical clutch outer having an annular plate portion mounted on one end thereof with a clutch inner of the second clutch being arranged between a clutch inner of the first clutch and the annular plate portion is disclosed in German Patent No. 4332466.
However, in the twin clutch device disclosed in German Patent No. 4332466, the first clutch and the second clutch are brought into a connection state by applying an external force. Thus, in providing the twin clutch device to a gear transmission, it is necessary to constantly apply the external force to the twin clutch device whereby the device is undesirable. In view of the above, it is desirable to provide a construction wherein the first clutch and the second clutch are brought into a disconnection state when the external force is applied. However, since the clutch inner of the second clutch is configured to be arranged between the annular plate portion of the clutch outer provided to the first clutch and the clutch inner of the first clutch, it is difficult to simply constitute the structure which can bring the first clutch and the second clutch into a disconnection state by applying the external force.
A twin clutch device is known for applying a control force for changing over a disconnection/connection state to first and second clutches which are arranged coaxially together with electrically-operated motors that are provided that individually correspond to the first and second clutches as disclosed in Patent Document EP-A-1400715.
However, in the twin clutch device disclosed in EP-A-1400715, it is necessary to provide the pair of electrically-operated motors which individually correspond to the first and second clutches. Thus, in addition to an increase in the number of parts, the structure becomes complicated. In addition, a manufacturing cost is increased and the twin clutch device becomes large-sized.
A twin clutch device is known which is configured to coaxially connect clutch outers of first and second clutches using bolts. See, for example, JP-A-61-153023.
However, in the structure which fastens both clutch outers using bolts as in the case of the twin clutch device disclosed in JP-A-61-153023, an outer circumferential diameter of the clutch outer is increased due to the bolt injector fastening thus leading not only to a large-sizing of the twin clutch device but also an increase in the number of parts and an increase in the number of man-hours for assembling.